The present invention relates to a blow-off nozzle structure applicable to various kinds of vessels containing water including a whirlpool bath, and more particularly to such blow-off nozzles which can automatically vary the blow-off volume of water continuously.
Conventionally various improvements have been made on the bathtub and one of such improvement is found in a whirlpool bathtub disclosed in U.S. Pat. No. 4,797,958. In this patent specification, a bathtub equipped with an improved hydromassage system is disclosed.
The bathtub is substantially characterized by a plurality of nozzles attached on the walls of the bathtub, wherein each nozzle comprises a plug which is normally closed so as to separate in a sealed manner the delivery and the supply lines from the container part of the bathtub. With the plug, there is also associated a manually actuated conduit for regulating the flow volume. Provision is also made for sensors sensitive to the level of the water in the bathtub and to the pressure of the water in the delivery line, for controlling the automatic discharge of the hydromassage system, the operation of the tap and the circulating pump.
The above blow-off nozzle, however, suffers from the following drawbacks. Namely, although it can automatically shut or open the nozzle with the actuation of a solenoid valve, it is impossible for the nozzle to automatically regulate the blow-off volume of water finely and continuously. Although in U.S. Pat. No. 4,797,958, as means for regulating the flow volume of the water, a conduit is adjustably mounted on the front portion of the nozzle, such adjustment must be effected manually resulting in an extremely cumbersome operation.
Furthermore, although within the nozzle, the flow of water is throttled to produce a Venturi effect and air is incorporated into the flow of water, no vortex is formed in the water prior to the air mixing operation, the air mixing efficiency is less than optimal, thereby the massaging effect is also less than optimal.
Accordingly, it is an object of the present invention to provide a blow-off nozzles structure capable of automatically varying the blow-off volume of water which can overcome the above drawbacks of the conventional nozzle structure.
It is also an object of the present invention to provide a blow-off nozzle structure which can increase the amount of air mixed into the blown-off water so that the massaging effect is highly improved.